NOUN (1)

1. any of various pale or light colors;


ADJECTIVE (2)

1. lacking in body or vigor;
- Example: "faded pastel charms of the naive music"

2. delicate and pale in color;
- Example: "pastel pink"

The Collaborative International Dictionary of English v.0.48:

Pastel \Pas"tel\, n. [F.; cf. It. pastello. Cf. Pastil.]
   1. A crayon made of a paste composed of a color ground with
      gum water. [Sometimes incorrectly written pastil.]
      "Charming heads in pastel." --W. Black.
      [1913 Webster]

   2. (Bot.) A plant affording a blue dye; the woad (Isatis
      tinctoria); also, the dye itself.
      [1913 Webster]

WordNet (r) 3.0 (2006):

pastel
    adj 1: lacking in body or vigor; "faded pastel charms of the
           naive music"
    2: delicate and pale in color; "pastel pink"
    n 1: any of various pale or light colors

Moby Thesaurus II by Grady Ward, 1.0:

95 Moby Thesaurus words for "pastel":
   air brush, art paper, black and white, brouillon, brush,
   camera lucida, camera obscura, canvas, cartoon, chalk, charcoal,
   charcoal drawing, chiaroscuro, crayon, creamy, delicate,
   delineation, design, diagram, doodle, draft, drawing,
   drawing paper, drawing pencil, drier, easel, ebauche, eggshell,
   esquisse, fair, fixative, flat, gloss, graph, ground, iridescent,
   lay figure, light, light-colored, light-hued, line drawing,
   maulstick, medium, mellow, mother-of-pearl, nacreous, opalescent,
   paint, paintbrush, pale, palette, palette knife, pastel color,
   patinaed, pearly, pen-and-ink, pencil, pencil drawing, pigments,
   quiet, rough copy, rough draft, rough outline, sad, scratchboard,
   semigloss, siccative, silhouette, silver-print drawing, simple,
   sinopia, sketch, sketchbook, sketchpad, sober, soft, soft color,
   soft-colored, soft-hued, softened, softness, somber, spatula,
   spray gun, study, stump, subdued, subtle, subtle color, sweet,
   tender, tracing, varnish, vignette, whitish